Making amorphous steel in air by rare earth microalloying

Recently great advancement in the fabrication of structural amorphous steels (SASs) with large cross-section sizes has been obtained. One of the remained key problems for the manufacturability and the application of SASs is that their glass-forming ability is very sensitive to the processing environments. Here we present the discovery that the bulk amorphous alloy Fe₄₄Mn₁₁Cr₁₀Mo₁₂C₁₅B₆Ho₂ has high oxygen resistance and can be prepared by conventional copper-mold casting method in air atmosphere. Rod-shaped amorphous samples of diameter up to 6 mm at least have been fabricated successfully. This amorphous steel alloy showed high glass-forming ability and good manufacturability. The beneficial effects of the addition of holmium on the glass-forming ability and oxygen resistance during the SAS formation are explored.